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Associations of meteorology with adverse pregnancy outcomes: a systematic review of preeclampsia, preterm birth and birth weight.

Beltran AJ, Wu J, Laurent O - Int J Environ Res Public Health (2013)

Bottom Line: Patterns of decreased gestational lengths have been observed for births in winter, as well as summer months.Most analytical studies also report decreases in gestational lengths associated with heat.Available results should encourage further etiological research aiming at enhancing our understanding of the relationships between meteorology and adverse pregnancy outcomes, ideally via harmonized multicentric studies.

View Article: PubMed Central - PubMed

Affiliation: Program in Public Health, Anteater Instruction & Research Bldg (AIRB), 653 East Peltason Drive, University of California, Irvine, CA 92697, USA. junwu@uci.edu.

ABSTRACT
The relationships between meteorology and pregnancy outcomes are not well known. This article reviews available evidence on the relationships between seasonality or meteorology and three major pregnancy outcomes: the hypertensive disorders of pregnancy (including preeclampsia, eclampsia and gestational hypertension), gestational length and birth weight. In total 35, 28 and 27 studies were identified for each of these outcomes. The risks of preeclampsia appear higher for women with conception during the warmest months, and delivery in the coldest months of the year. Delivery in the coldest months is also associated with a higher eclampsia risk. Patterns of decreased gestational lengths have been observed for births in winter, as well as summer months. Most analytical studies also report decreases in gestational lengths associated with heat. Birth weights are lower for deliveries occurring in winter and in summer months. Only a limited number of studies have investigated the effects of barometric pressure on gestational length or the effects of temperature and sunshine exposure on birth weight, but these questions appear worth investigating further. Available results should encourage further etiological research aiming at enhancing our understanding of the relationships between meteorology and adverse pregnancy outcomes, ideally via harmonized multicentric studies.

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Related in: MedlinePlus

Pooled relative risks and 95% credible interval for the variation in preeclampsia incidence by month of conception (N = 530,160 births).
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Related In: Results  -  Collection

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ijerph-11-00091-f001: Pooled relative risks and 95% credible interval for the variation in preeclampsia incidence by month of conception (N = 530,160 births).

Mentions: Six studies examining preeclampsia focused on seasonality of conception (Table A1). Five of them were conducted in non tropical settings and reported month-to-month variations that allowed meta-analysis [14,15,16,17,18]. The result of the meta-analysis including 530,160 births (Figure 1) shows an increase in risks of preeclampsia from the coldest to the warmest months of conception, followed by a decrease from the warmest to the coldest months of conception, although pooled relative risks were statistically significant only for certain months. One single study in Australia contributed to 80% of pregnancies included in the meta-analysis [16]. After excluding this study, we still observed a similar temporal pattern, although most relative risks are not significant anymore (Table A2). One study conducted in the tropical setting of Thailand could not be pooled with the other studies included in the meta-analysis, which were all conducted in non-tropical settings. This study reported a higher risk of preeclampsia for conception in dry than in wet season [19].


Associations of meteorology with adverse pregnancy outcomes: a systematic review of preeclampsia, preterm birth and birth weight.

Beltran AJ, Wu J, Laurent O - Int J Environ Res Public Health (2013)

Pooled relative risks and 95% credible interval for the variation in preeclampsia incidence by month of conception (N = 530,160 births).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3924438&req=5

ijerph-11-00091-f001: Pooled relative risks and 95% credible interval for the variation in preeclampsia incidence by month of conception (N = 530,160 births).
Mentions: Six studies examining preeclampsia focused on seasonality of conception (Table A1). Five of them were conducted in non tropical settings and reported month-to-month variations that allowed meta-analysis [14,15,16,17,18]. The result of the meta-analysis including 530,160 births (Figure 1) shows an increase in risks of preeclampsia from the coldest to the warmest months of conception, followed by a decrease from the warmest to the coldest months of conception, although pooled relative risks were statistically significant only for certain months. One single study in Australia contributed to 80% of pregnancies included in the meta-analysis [16]. After excluding this study, we still observed a similar temporal pattern, although most relative risks are not significant anymore (Table A2). One study conducted in the tropical setting of Thailand could not be pooled with the other studies included in the meta-analysis, which were all conducted in non-tropical settings. This study reported a higher risk of preeclampsia for conception in dry than in wet season [19].

Bottom Line: Patterns of decreased gestational lengths have been observed for births in winter, as well as summer months.Most analytical studies also report decreases in gestational lengths associated with heat.Available results should encourage further etiological research aiming at enhancing our understanding of the relationships between meteorology and adverse pregnancy outcomes, ideally via harmonized multicentric studies.

View Article: PubMed Central - PubMed

Affiliation: Program in Public Health, Anteater Instruction & Research Bldg (AIRB), 653 East Peltason Drive, University of California, Irvine, CA 92697, USA. junwu@uci.edu.

ABSTRACT
The relationships between meteorology and pregnancy outcomes are not well known. This article reviews available evidence on the relationships between seasonality or meteorology and three major pregnancy outcomes: the hypertensive disorders of pregnancy (including preeclampsia, eclampsia and gestational hypertension), gestational length and birth weight. In total 35, 28 and 27 studies were identified for each of these outcomes. The risks of preeclampsia appear higher for women with conception during the warmest months, and delivery in the coldest months of the year. Delivery in the coldest months is also associated with a higher eclampsia risk. Patterns of decreased gestational lengths have been observed for births in winter, as well as summer months. Most analytical studies also report decreases in gestational lengths associated with heat. Birth weights are lower for deliveries occurring in winter and in summer months. Only a limited number of studies have investigated the effects of barometric pressure on gestational length or the effects of temperature and sunshine exposure on birth weight, but these questions appear worth investigating further. Available results should encourage further etiological research aiming at enhancing our understanding of the relationships between meteorology and adverse pregnancy outcomes, ideally via harmonized multicentric studies.

Show MeSH
Related in: MedlinePlus